I lowered the amount of salt in the recipe as it has a tendency to create holes when drying, but there is a smooth finish when I added lime powder for some reason. You could chuck in some crushed Calcium tablets if you don't have any lime powder at hand.

Step 2: How to make an Impression

I covered the back of several leaves I collected with a generous coating of mineral oil.

The back veins are deeper on the leaves than the front and are perfect for casting.

Roll out a piece of clay that is larger than your object for casting. Here I rolled the playdough onto baking paper and pressed it flat with a piece of plastic wrap.

hi, it is a good idea but if you use cold porcelain dough or salt dough it will not take that much timeto dry the cp will take about a day and the salt one but it in the oventhe thinner the leaf the faster it drys

Flour/salt doughs tend to be porous (and leach salt) so the chocolate would stick (and licking it off the mold would taste nasty). The cold porcelain might work better, a vacuum former could create the same molds that you can buy at the candy store.

thanks for your comment, true the salt on chocolate might taste bit funny, but I'm not sure pva is safe to ingest - particular some glues made o'seas might include formelhyde not safe for those expecting. otherwise all the ingredients above are pretty safe with chocolate